The Words I Didn't Say
by ipreferwestside
Summary: Maybe he'd catch the disappointment in her voice at his silence, the longing she wasn't quite sure she could disguise. A season 4 AU set during the "47 Seconds" arc. For Lou.


_I've lived, I've loved, I've lost, I've paid some dues, baby  
We've been to hell and back again  
Through it all you're always my best friend  
For all the words I didn't say and all the things I didn't do  
Tonight I'm gonna find a way  
_All About Loving You – Bon Jovi

* * *

 **THE WORDS I DIDN'T SAY**

* * *

"You should go talk to him, Kate."

Kate gave Lanie a look. She'd called her friend shortly after returning from a drink with Colin Hunt, claiming she was conflicted on her feelings for the Scotland Yard Inspector. But, as usual, Lanie had seen right through her, and the conversation had almost immediately turned to Castle. "That's not what you're supposed to say," she argued as she paced across Lanie's living room.

Lanie shrugged. "First of all, you're here so I can tell you what you NEED to hear, not what you WANT to. Second of all, you know I'm right. Showing up at the crime scene like he did, with the flight attendant and Ferrari? Castle's acting out. He's obviously upset about something, and he's taking it out on you."

"Or he's saying that he's moved on. He said he wanted 'fun and uncomplicated,' Lanie. That is the exact opposite of me." Kate groaned and sat on the other end of the couch, curling her legs underneath her. "Did I completely miss my chance?"

"Go talk to him."

"He's probably out with that flight attendant. Or…" Kate trailed off at the thought that he could be home, but with _her._ "I'll call him first."

Lanie surged forward and grabbed Kate's phone off the coffee table, holding it away from Kate. "Nope. Just go over there. Don't call him, don't think about it, just go."

* * *

Kate was on her way to Castle's loft when she got a call to another crime scene. She spent the 20-minute drive arguing with herself about whether she should call Castle. It was late; he'd been going out with the flight attendant; he'd probably ignore her call anyway. Finally, she sighed loudly and slammed her fist against the steering wheel.

Calling him to the scene would get him away from… _what was her name? Jasmine? Jessica?_

She dialed his number before she could talk herself out of it, but the call went to voice mail.

"Hi, you've reached Richard Castle, lucky you. Leave a message."

She rolled her eyes at his message, at his drawl when he said "lucky you," cursing her body heat to rise at the sound of his voice, even thought it was a recording.

She really shouldn't have called him.

Regardless, she left a quick message with the address of the scene and instructions that he didn't have to join but she'd be remiss if she didn't let him know. Maybe he'd catch the disappointment in her voice at his silence, the longing she wasn't quite sure she could disguise. _Serve him right for being out with what's-her-name. Jennifer? Jaclyn?_

Surprisingly, she saw Castle pull up just a few minutes after she'd arrived; he must have listened to her message almost immediately. _Maybe he wasn't out with J…J…Jacinda. Right. Jacinda._ He ignored her, though, until she approached him.

"You got my message," she said by way of greeting, trying to ignore the knot in her stomach.

Castle glanced at her briefly before turning his attention back to the scene in front of them. "Yeah."

She waited a few moments to see if he'd continue, but he stayed silent, his jaw set, eyes fixed on the scene in front of them. "Jacinda go home?"

"She had to go into work."

"Oh." Kate turned her attention back to the scene. They were in front of an apartment building, the victim allegedly inside, but the suspect had taken some residents hostage, and they had to wait for SWAT to clear the building. The all clear came within a few minutes, minutes spent in an awkward silence, but they were soon thrust into chaos when the suspect ran.

"That way!" Castle shouted after a moment, pointing towards the figure of a man running from the scene. He and Kate took off, hot on the suspect's heels, but he was faster than the two of them, and they soon lost him when he turned into an alley.

Kate grabbed Castle's arm to stop him and stepped in front of him, gun drawn, moving cautiously around the corner. "NYPD!" she called out, "come out with your hands up!" She heard the creek of a door, and crept down the alley, Castle inches behind her. Partway down the alley she noticed a door slightly ajar, and she glanced back at Castle, jerked her head towards the dark opening as if to say _watch my back in there._

She shouldn't have to remind him, because he's her partner.

At least, he has been.

They crossed through the door slowly, Kate's flashlight illuminating what seemed to be an empty room. She and Castle looked around, confusion muddling her thoughts and lining his face.

"What the…" Castle mumbled.

Kate swept her flashlight along the walls, the corners and edges, looking for a window or another door that the suspect could have escaped through. "Where did he go?"

Castle followed the beam of the flashlight. "He probably—"

They both froze when they heard the door shut behind them, the minimal light from outside being cut off and plunging the room into almost complete darkness, the only light source from her flashlight.

"Shit," Kate whispered, and she cursed again when she saw a vapor start to trickle in from underneath the door. "Castle…"

Castle followed her gaze and grimaced. "Dammit. What the hell is that?"

"I have no idea but we gotta get out of here." Kate tried to ram her shoulder against the door, grunting when she just bounced against it. _Damn, that hurt._ "Castle, you're stronger than me, you try."

Castle tried a few times, but the door wouldn't budge for him, or for both of them when they rammed it together. Finally, after a few minutes, they leaned against opposite walls, panting.

"What the hell is that vapor?" Kate asked, mostly just to break the silence. It was getting into her system; she was starting to feel lightheaded, almost like she was tipsy, even though she hadn't had anything to drink since the one she'd had with Hunt several hours before.

Castle sighed and slumped against another wall. "Beats the hell out of me. I should have just stayed home; I didn't really want to come anyway."

"What do you mean?" Kate stared at him, even though she could barely see him in the low light. But she could make out enough to see him slide to the floor.

"I mean that I don't want to do this anymore. I can't just watch you act like nothing's wrong."

"Castle..."

"No, Beckett. You think everything's fine, that we're not broken. But yesterday I watched you walk out of the precinct on another man's arm, and I couldn't do a damn thing about it because it wasn't my place."

Kate paused, confused. What was he talking about? Oh, when she and Hunt went to the British Consulate party? _Jesus._ "You think that meant something? It was _undercover_ , Castle, that's it."

"So why'd you meet him for a drink tonight?"

"What-you followed me?"

"Yes." His voice was cold, no apology whatsoever.

Her hands clenched into fists. The nerve of the man! "What the hell, Castle?"

"I heard him ask you so I waited outside to see if you'd actually go. I needed to know how far you were going to take it."

"You said you needed 'fun and uncomplicated,' and I didn't see the harm in meeting someone for a badly-needed drink." Kate couldn't believe it; Castle had followed her to the airport, just to what, check up on her?

"Yeah, well, it looked like you were having a great time, laughing and flirting."

"I wasn't flirting. He told a joke, I laughed, we finished our drinks, and went our separate ways. And how dare you tell me how I should act when _you're_ the one who brought a fling to _my_ crime scene!"

"Oh, like you care what I do with my spare tme."

Okay, sarcasm. She can deal with this. "When it affects work, yeah, I do."

"Who's work did it affect? Because it sure as hell didn't affect mine. Oh, unless _you_ let _my_ personal life get in the way of _your_ job? Now that's just pathetic."

"Who's the pathetic one? You followed me to the airport simply to see if I was gong to sleep wtih someone! You want to call me pathetic, you betterr take accoountability for your own actions." Okay, whatever was in that vapor had to be causing all of this, all of this obvious repressed conversation to come to the-

"You want to talk about that? I'm not the one who's been lying."

Kate froze. _What?_ "What are you talking about?"

Castle scoffed, as if he was expecting her reaction. "Your shooting? What you supposedly don't remember? I heard what you said in that interrogation, that you remembered, so don't try to deny it."

Kate sighed, defeated. If he was going to bring it up now, she was going to clear the air, once and for all. "Fine, I won't deny it. Yes, i remember. I've remembered for a long time."

Castle was silent for a few long moments before speaking, his voice quiet, almost a whisper. "Why didn't you say anything?"

"Because I couldn't."

"You mean you didn't want to put me down. You liked having me around. If you told me how you really felt I would have left and you didn't want that." He paused, but continued before she could say anything. "You know I'm right, Kate."

"No, you're wrong. I was scared, yes. Scared that you didn't actually love me. That you said you did because I was dying, because maybe you felt that way in that moment. But then I started to think that maybe when I was gone that summer, that you didn't feel the same way anymore. And I couldn't bear the thought of telling you how I felt, how I _feel_ , and you rejecting me."

"Reject you? Jesus, Beckett, I've been practically throwing myself at your feet!"

"Okay, look, can we take a step back? Be completely honest?"

"Pretty sure that's all we've been doing here, is being honest."

"I'm ser-"

"Wait, did you say 'feel,' like present tense? How you feel?"

"Yes."

"How do you feel, Kate?"

"Honestly?"

"What do you think?"

"Fine. I love you. Happy? I am in love with you and I have been for a long time. I've been seeng a therapist, trying to get my head back on straight, trying to be the woman you deserve. I lied about remembering my shootng, remembering what you said. But I can't lie anymore. I don't want to. Because we're trapped in this godforsaken room and who knows how long we'll be here, and I just need to get it all out. And I wish I'd told you sooner, before you moved on. Becuase now I've lost my chance."

"No you haven't."

"What?"

Castle stood and made his way over to sit next to her. "You haven't lost your chance, Kate. You've never lost it, because I'll always be yours. Look, when we get out of here, you're coming to my place, and we're going to figure this out."

Kate nudged closer so their thighs were barely touching, and she brushed her hand against his. "I think we already did. Whatever was in that vapor, it kind of caused all of this." She leaned up to look at him as her flashlight started to flicker. "You still love me?" she asked quietly, almost a whisper.

Castle chuckled. "Yeah, I'll say. I've been thinking of leaving, of not working anymore cases, because I couldn't bear the thought of being so close to you without being able to do anything." He turned his hand over, his palm facing the ceiling, and watched as she slipped her hand into his. "I love you, Kate. I've never stopped."

Kate squeezed his fingers. "I love you too, Rick." She leaned into him, and their lips had barely brushed together when she heard noise from outside.

"Beckett! Castle!"

She pulled away with something that sounded suspiciously like a whimper. "Shit," she whispered.

Castle smiled. "We'll continue this later," he promised with another squeeze of her hand. He stood and helped her up, and they brushed the dirt off their pants before making their way to the door. "Ryan! Esposito! We're in here!"

* * *

An hour later, after they'd been rescued and had blood drawn, Lanie approached them with a smirk on her face.

"You guys can leave," she instructed them. "You don't need any extra treatment. It'll be out of your system within a few hours."

Castle rubbed his arm where they'd drawn blood. "What was it? Should we be worried about potential long-term side effects?"

Lanie gave them both a pointed look. "Unless there are side effects from your conversation in that room, there's nothing to worry about."

Kate crossed her arms in what she hoped was an intimidating posture; Lanie obviously knew her tricks, though, because her smirk just got bigger. "Lanie, what were we poisoned with?"

"You weren't poisoned, exactly," Lanie explained. "If you had been, you'd both be in the hospital. No, you were subjected to an aerosolized version ofsodium pentothal. It's a drug used primarily in general anesthetic. Basically, it makes you react like you would if you've been drinking. It's like a—"

"Truth serum."

"Truth serum."

Kate and Castle's eyes met, and Castle smirked. "I guess it works," he said with a shrug, his voice teasing.

Kate just rolled her eyes. "Yeah, apparently it does. So what of it, Lanie? Can we go?"

Lanie looked back and forth between her two friends. "Yep, you're clear to go. Just try t take it easy. Its effects are similar to intoxication, and your body will probably react the same way, try to get it out of your system."

"Thanks, Lanie." Kate paused after a few steps and looked back at Castle. "Are you coming?"

"Oh, yeah."

They met Ryan ad Esposito on their way from the crime scene; they'd caught the suspect and the evidence against him was solid, so it looked to be an open-and-shut case. With extra paperwork, of course.

But at the moment, Kate didn't care. The moment she and Castle – at her heels, as usual – were out of eyesight, she grabbed his coat lapels and shoved him against the nearest wall.

"Kate, what—"

She interrupted him with her lips rough against his, knuckles white as they gripped his coat. One – or both – of them moaned when her tongue slicked past his lips to find him open and waiting, and she let him turn them around so her back was pressed against the building. She moaned again when his thigh nudged between hers and she sank down on it, rolling her hips slowly, needing more friction.

Finally, after a few minutes, her common sense managed to get through the fog of lust that had taken over her entire body, and she pulled away, panting slightly.

Castle kept his eyes closed for a few extra moments, his forehead against hers, even their breathing in sync. "Kate," he whispered, drawn-out, almost like a prayer.

Kate lightly bumped his forehead. "Weren't we going to your place?"

"Yeah." Castle chuckled softly. "Truth serum, huh?"

Kate smiled and laced her fingers through his, leading him towards his car. "Yeah. You think we can be open and honest without it?"

Castle winked at her. "I think we can do a lot more than that."

* * *

 _This fic is a birthday present to Her Eminence, the Prompt Overlord, and someone I am proud to consider a dear friend, Lou. She gave me the prompt "truth serum during "47 Seconds" arc" and, well, I hope you liked it! Happy Birthday!_


End file.
